In addition, immunohistochemical staining showed that N3ICD induced PTEN expression and inhibited Ki-67 in N3ICD xenograft tumor model, at the same time, PTEN knockdown resulted in loss of PTEN expression and increased Ki-67 staining in the N3ICD + shPTEN group, suggesting that Notch3 overexpression may inhibit tumor formation by regulating PTEN expression. This evidence concerns the gene PTEN and neoplasm.